Developing a Taxonomy for Coding Ambulatory Medical Errors: A Report from the ASIPS Collaborative

Background: Multiple taxonomies are used to classify medical errors. Most are conceptually based with limited empirical evidence on their utility to characterize processes leading to errors. We analyzed the utility of the Dimensions of Medical Outcomes taxonomy to describe medical errors and their relationship to harm. Methods: Individuals in 34 primary care practices reported medical errors to a Patient Safety Reporting System. Based on the first 357 reports, we modified a multi-axial taxonomy to improve the description of primary care errors. We then applied 337 of 421 available taxonomy codes to 608 error reports. Analyses included basic frequencies, cross tabulations, and odds ratios to examine the ability of the taxonomy and its underlying constructs to describe patient safety events and their relationship to harm. Results: Four individual codes were associated with harm, including therapeutic intent of an activity, language barriers, and errors of judgment. Harm was also associated with 10 constructs within the taxonomy hierarchy and 8 derived constructs. These constructs included communication from another office, mistimed procedures, medication errors, and involvement of the treating clinician. Harm was not associated with incorrectly performed procedures or failure to perform procedures or general information flow within, into, or out of the office. Discussion: Approaches to classifying medical errors vary widely. While our highly detailed approach required a relatively large number of reports to be useful for examining individual codes, it allows the use of different analytical approaches to help uncover processes in primary care that lead to medical errors resulting in patient harm. Conclusion: Taxonomies developed to understand medical errors should be analyzed empirically, using quantitative and qualitative approaches to demonstrate their utility for describing medical errors, as well as the level of detail required for varying uses